Hematology
SYSTEMATIC REVIEW
● Sys. Review
Siltuximab shows partial response in two iMCD-IPL cases with xanthelasma; skin lesions unchanged
Frontiers in Medicine
Published April 1, 2026
DOI ↗
A case report from a Canadian center in British Columbia describes two Asian women in their 5th decade diagnosed with the idiopathic plasmacytic lymphadenopathy (IPL) subtype of idiopathic multicentric Castleman disease (iMCD-IPL). Both patients presented with normolipemic bilateral xanthelasma palpebrum, anemia, inflammation, and polyclonal hypergammaglobulinemia. The intervention was treatment with siltuximab. No comparator was reported.
Regarding main results, both patients achieved a partial clinical and biochemical response to siltuximab. However, their xanthelasma palpebrum showed no change with this therapy. The authors conducted a literature search which identified three separate cases of unicentric Castleman’s disease (UCD) where xanthomas regressed after surgical resection of the affected lymph node. This suggests a potential pathophysiological association between Castleman disease and xanthomas, though it is not proven.
Safety and tolerability data were not reported for these two cases. Key limitations include the nature of the evidence, which is a case report of only 2 patients. The association with xanthomas is based on a separate literature review of UCD cases, not on the iMCD-IPL patients treated with siltuximab. Practice relevance is restrained; this report adds to the phenotypic description of iMCD-IPL and highlights an observed co-occurrence with xanthelasma that did not respond to IL-6 blockade, in contrast to regression seen post-resection in some UCD cases.
Doctors in Canada described the cases of two women in their 40s with a rare immune system disorder called idiopathic multicentric Castleman disease (iMCD). Both women also had xanthelasma, which are yellowish patches of cholesterol that can appear on the eyelids. Their blood tests showed no typical high cholesterol levels that usually cause these patches.
The women were treated with a medication called siltuximab, which is approved for their type of Castleman disease. Their main disease symptoms, like anemia and inflammation, showed a partial improvement with this treatment. However, the xanthelasma on their eyelids did not get better or go away.
The doctors also looked at past medical reports and found three other cases where patients with a different form of Castleman disease had similar skin growths that did disappear after surgery. This suggests there might be a link between the immune problems in Castleman disease and the development of these skin patches, but it is far from proven.
It is crucial to remember this is just a detailed story about two patients. Their experience cannot tell us what will happen for other people. More research involving many more patients is needed to understand if there is a real connection between these two conditions and why the treatment helped the disease but not the skin issue.
What this means for you: A report on two patients suggests a possible link between a rare disease and eyelid cholesterol deposits, but much more research is needed.
View Original Abstract ↓
BackgroundIdiopathic plasmacytic lymphadenopathy is a newly recognized subtype of idiopathic multicentric Castleman disease (iMCD-IPL) and often mimics IgG4-related disease (IgG4-RD). We present two of the first cases of iMCD-IPL diagnosed in British Columbia, Canada. Both patients had normolipemic bilateral xanthelasma palpebrum, which has not previously been reported in iMCD-IPL.Case reportBoth patients were Asian women in the 5th decade who presented with anemia, inflammation, polyclonal hypergammaglobulinemia (PHGG), and xanthelasmas. IgG4-RD was initially suspected, but upon review of the lymph node histology and careful clinicopathological correlation, both were found to have iMCD-IPL with plasmacytic histology. Biopsies of the xanthelasmas revealed foamy macrophages consistent with common xanthelasmas. Both patients had partial clinical and biochemical response to siltuximab, but no change in xanthelasmas. We searched the literature and identified three cases of unicentric Castleman’s disease (UCD) with xanthomas, systemic inflammation and PHGG. These three patients showed marked improvement in both systemic symptoms and xanthomas after resection of the UCD.ConclusionWe report two patients with normolipemic xanthelasmas and iMCD-IPL whose xanthelasmas did not regress with siltuximab. However, the regression of xanthomas in three cases of UCD from the literature suggest a potential pathophysiological association between Castleman disease and xanthomas.
